Dead, stuck and hot pixels — what's the difference?
A dead pixel is permanently off: it stays black on every background because its transistor gets no power, and it's usually a physical fault that can't be fixed. A stuck pixel is the opposite — one sub-pixel (red, green or blue) is jammed on, so you see a small coloured dot that doesn't change with the image behind it. A hot pixel stays fully lit (white) all the time. The fastest way to tell them apart is to flood the screen with pure colors: a dead pixel is obvious on a white screen, while a stuck or hot pixel jumps out against black. This tool fills your display edge-to-edge with each color in true fullscreen so nothing on the panel is hidden behind browser toolbars.
How the stuck-pixel fixer works
Stuck pixels often respond to being rapidly driven through their full colour range. The fixer draws fast, full-saturation RGB noise over the screen, forcing every sub-pixel to switch on and off many times a second — the digital equivalent of exercising a jammed muscle. Run it over the affected area for anywhere from ten minutes to half an hour; stubborn pixels sometimes need a few sessions. A gentle massage of the exact spot with a soft, slightly damp cloth (screen off) while the flicker runs can improve the odds. It's not guaranteed — truly dead pixels won't respond — but it's a free, non-invasive first step before considering a warranty claim.
Beyond pixels: banding, bleed and clouding
The same solid-color screens reveal panel quality issues that a normal desktop hides. The gradient screen shows colour banding — visible bands or steps instead of a smooth transition — which points to a lower-bit-depth panel or aggressive compression. A full-black screen in a dark room exposes backlight bleed (bright patches at the edges) and clouding (uneven greyish blotches), both common on LCD panels. Solid grey and white help spot uniformity problems and yellowing. Because everything is drawn locally in your browser at your screen's native resolution, what you see is your panel's real behaviour, not an artefact of any upload or compression.
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- True fullscreen solid-color cycling through 11 colors (white, black, red, green, blue, cyan, magenta, yellow and three grays) using the native Fullscreen API — no browser chrome to hide faults.
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- Stuck-pixel fixer that flashes rapid full-saturation RGB noise across the screen with an elapsed timer, the standard technique for reviving a stuck sub-pixel.
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- Gradient / banding screen: a smooth black-to-white ramp that reveals 8-bit colour banding, panel clouding and backlight bleed.
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- One-tap color jump grid plus keyboard and click/tap navigation (arrows, space, click to advance).
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- Auto-cycle mode that steps through every color hands-free at a steady interval.
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- Auto-hiding on-screen HUD so nothing obscures the pixels you're inspecting.
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- Works on any device — desktop monitor, laptop, phone, tablet or TV browser — and uploads nothing.
